The crime happened 50 years ago this month, on a Friday the 13th. A young woman met a vile end at the hands of a knife-wielding maniac in the courtyard of her Queens apartment building. In a city as big and fast-paced as New York, she could have easily become a statistic, another urban casualty tossed into the maw of forgetfulness. But Kitty Genovese’s name endures. And in his new book, Kevin Cook takes a revisionist look at this infamous crime, the facts of which are not as settled as the public has been led to believe.

After the news media reported that 37 of Genovese’s neighbors had witnessed her murder, standing by without lifting a finger to help, pundits across the nation decried social apathy. The loss of community spirit, of a shared sense of responsibility, augured badly for the future. Students at high schools and colleges started learning about the bystander effect, a catchphrase coined by psychologists to explain the appalling behavior of Genovese’s neighbors.

But Cook corrects misinformation. Only two people — not 37 — actually witnessed Genovese’s attack (a handful of others were woken by her screams). This cowardly pair turned their backs on her as she was repeatedly stabbed; the rest were unsure what was happening. Also contrary to myth, the police were called. And even though the killer could have still been lurking, a brave woman rushed to the fatally wounded victim’s side and tried to comfort her. Could more have been done? Absolutely. But for all their faults, Genovese’s neighbors were not the “residential barbarians” depicted by the media.

The man chiefly responsible for this was A.M. Rosenthal, the metropolitan editor of The New York Times. Rosenthal had lunch with the police commissioner shortly after the culprit, a 29-year-old keypunch operator named Winston Moseley, was apprehended. The commissioner had a problem. In addition to Genovese, Moseley had falsely confessed to another murder. To keep the Times from muddying the prosecutorial waters, the commissioner brought up the neighbors’ supposed inaction. Rosenthal took the bait. After it was featured on the front page, the story went viral, circa 1964.

Cook writes tautly, with skillful pacing and absorbing characterization. Occasionally, however, his attention to historical detail can be disconcerting. There is nothing wrong with providing context, but the author pads his narrative with lengthy discussions of the Brooklyn Dodgers, the World’s Fair and other subjects that while interesting have little do with the murder.

But he generally stays focused on the essentials. This is about two lost souls: one full of life, the other barely human. On the surface, Genovese’s killer had it made as a black man in the pre-Civil Rights Act era. A middle-class homeowner with a wife, two kids and five German shepherds, he had a well-paying job and an above-average IQ. But he was a sociopath who had prowled the streets for weeks before spotting Genovese, during which he raped several women, one of whom he set on fire.

Genovese was a 28-year-old Italian-American bar manager who lived with her girlfriend, Mary Ann Zielonko. Cook’s interview with Zielonko is heartbreaking; she clearly loved Genovese. Neither side raised Genovese’s sexuality at Moseley’s trial; it was considered irrelevant. Nevertheless Cook goes into detail about the threats and obstacles gay couples faced in the early 1960s, when laws against same-sex behavior were enthusiastically enforced. (Fair-minded readers will be outraged at Zielonko’s treatment by homophobic police after the murder.) Genovese didn’t let this, or anything else, get her down. Everybody seemed to like her.

You will feel queasy when you learn what Moseley did to this nice lady after he stabbed her. Unfortunately, she was alive throughout the disgusting ordeal. Moseley knew no limits. A few years later, a prison doctor found a can of Spam shoved up his rectum, a ploy to be sent to the hospital, from which he escaped. He raped two women before he was recaptured.

But let us leave the damned in the pit and return to Genovese, whose name still resonates in our discourse. It was even used to justify the Iraq war. Perhaps the most haunting image in Cook’s book is at the end, when we find out the last words she heard, spoken in vain by Sophia Farrar, the neighbor who came to her aid: “Help is coming.”